Hidden Figures tells the neglected story of the black women mathematicians behind the scenes during the early days of NASA.

Katherine Johnson (Taraji P Henson) works as a computer in the backrooms of NASA as the fledgling agency tries to put a man in space. She is tapped to work out analytical geometry for hard-nosed director Al Harrison (Kevin Costner), and suffers the contempt of Paul Stafford (Jim Parsons) who resents her attempts to gain credit for her work on his project. Fellow mathematicians Dorothy Vaughan (Octavia Spencer) and Mary Jackson (Janelle Monae) have parallel struggles. Karl Zielinski (Olek Krupa) wants Jackson as his engineer, but she must jump through Jim Crow hoops to achieve that title, while Vivian Mitchell (Kirsten Dunst) offers no help to Vaughan in her quest to be given the title of supervisor of the coloured computers given that she’s doing the job. Their difficulties are mirrored by America failing to keep pace with the USSR.

Always be suspicious of important films, they are rarely good. And always be suspicious of films based on a true story, they usually make pig-swill of history and defensively claim artistic license even as they demand Oscars for their fearless dedication to telling true stories. Director Theodore Melfi and co-writer Allison Schroeder’s script is full of transparently bogus movie moments that are the hallmark of screenwriting designed purely to create Oscar ceremony excerpts: Costner desegregates NASA with a crowbar, Henson gives her boss the sort of haranguing that in reality precedes being escorted from the premises, and, in perhaps the most delirious touch of all, to symbolise how Johnson despite her important work had the door slammed in her face by white men, Melfi has Johnson hand over her important work and have the door slammed in her face. Indeed.

Spencer hasn’t changed her shtick since I disliked it in Ugly Betty but is Oscar-nominated for Supporting Actress. Spike Lee’s calculated tantrum reaped 6/20 black acting nominations this year, but Spencer is nominated when Greta Gerwig is not for 20th Century Women, and you wonder about that during Spencer’s jaw-dropping put-down of Dunst (who is obviously a snob not a racist). A put-down redolent of the current cultural moment’s disquieting joy in fault-finding witch-hunts which insist dissent from the (ever-changing) party line betrays a racist/sexist/et al mindset which might not even be conscious of its own white privilege/toxic masculinity/et al. Hidden Figures, like Supergirl, is rather effective when it gets off its soapbox. Monae translates her soul star charisma, Mahershala Ali plays quiet grace, Glenn Powell is an ebullient John Glenn, and the rise of IBM in rocketry is fascinatingly handled.

Hidden Figures is entertaining, despite missed opportunities to dig deeper into black identity via radical Levi Jackson (Aldis Hodge), but its depiction of history needs to be taken with a whole cellar of salt.